Added support of default zoom to statistical charts.

Telegram/SourceFiles/data/data_statistics.h

@@ -73,6 +73,11 @@ struct StatisticalChart {
 
 	std::vector<Line> lines;
 
+	struct {
+		float64 min = 0.;
+		float64 max = 0.;
+	} defaultZoomXIndex;
+
 	int maxValue = 0;
 	int minValue = std::numeric_limits<int>::max();
 

Telegram/SourceFiles/statistics/chart_widget.cpp

@@ -271,6 +271,9 @@ ChartWidget::Footer::Footer(not_null<Ui::RpWidget*> parent)
 : RpMouseWidget(parent) {
 	sizeValue(
 	) | rpl::start_with_next([=](const QSize &s) {
+		if (s.isNull()) {
+			return;
+		}
 		const auto w = float64(st::statisticsChartFooterSideWidth);
 		_width = s.width() - w;
 		_widthBetweenSides = s.width() - w * 2.;
@@ -1105,6 +1108,9 @@ void ChartWidget::setupFooter() {
 
 	_footer->xPercentageLimitsChange(
 	) | rpl::start_with_next([=](Limits xPercentageLimits) {
+		if (!_chartView) {
+			return;
+		}
 		const auto now = crl::now();
 		if (_details.widget
 			&& (_details.widget->xIndex() >= 0)
@@ -1407,9 +1413,14 @@ void ChartWidget::setChartData(
 	setupDetails();
 	setupFilterButtons();
 
+	const auto defaultZoom = Limits{
+		_chartData.xPercentage[_chartData.defaultZoomXIndex.min],
+		_chartData.xPercentage[_chartData.defaultZoomXIndex.max],
+	};
+	_footer->setXPercentageLimits(defaultZoom);
 	_animationController.setXPercentageLimits(
 		_chartData,
-		{ _chartData.xPercentage.front(), _chartData.xPercentage.back() },
+		defaultZoom,
 		_chartView,
 		_linesFilterController,
 		0);
@@ -1440,13 +1451,13 @@ void ChartWidget::setZoomedChartData(
 		ChartViewType type) {
 	_zoomedChartWidget = base::make_unique_q<ChartWidget>(
 		dynamic_cast<Ui::RpWidget*>(parentWidget()));
-	_zoomedChartWidget->setChartData(std::move(chartData), type);
 	geometryValue(
 	) | rpl::start_with_next([=](const QRect &geometry) {
 		_zoomedChartWidget->moveToLeft(geometry.x(), geometry.y());
 	}, _zoomedChartWidget->lifetime());
 	_zoomedChartWidget->show();
 	_zoomedChartWidget->resizeToWidth(width());
+	_zoomedChartWidget->setChartData(std::move(chartData), type);
 
 	const auto customHeader = Ui::CreateChild<Header>(
 		_zoomedChartWidget.get());

Telegram/SourceFiles/statistics/statistics_data_deserialize.cpp

@@ -70,6 +70,30 @@ Data::StatisticalChart StatisticalChartFromJSON(const QByteArray &json) {
 		}
 		result.measure();
 	}
+
+	{
+		const auto subchart = root.value(u"subchart"_q).toObject();
+		const auto defaultZoomIt = subchart.constFind(u"defaultZoom"_q);
+		auto min = int(0);
+		auto max = int(result.x.size() - 1);
+		if (defaultZoomIt != subchart.constEnd()) {
+			if (const auto array = defaultZoomIt->toArray(); !array.empty()) {
+				const auto minValue = array.first().toDouble();
+				const auto maxValue = array.last().toDouble();
+				for (auto i = 0; i < result.x.size(); i++) {
+					if (result.x[i] == minValue) {
+						min = i;
+					}
+					if (result.x[i] == maxValue) {
+						max = i;
+					}
+				}
+			}
+		}
+		result.defaultZoomXIndex.min = std::min(min, max);
+		result.defaultZoomXIndex.max = std::max(min, max);
+	}
+
 	const auto colors = root.value(u"colors"_q).toObject();
 	const auto names = root.value(u"names"_q).toObject();